Ureterotomy, hydropulsion?

RE: Ureterotomy, hydropulsion?

Anthony Todd — Tue, 22 Sep 2015 11:29:48 GMT

[quote user="gerard mclauchlan"] urethral relaxation in dog[/quote]

I would have thought the os penis would stop the dilatation being effective??

RE: Ureterotomy, hydropulsion?

Anthony Todd — Tue, 22 Sep 2015 11:26:27 GMT

Reobstruction rate at 24 hours was significantly lower when a 3.5F versus 5F urinary catheter was used.

Glad to see some evidence at last! Bloody in-dwelling catheters, in fact catheterisation of blocked cats causes as many problems as it relieves and the wider the catheter the more problems.

Most of the "reblocking" IMHO is actually urethral stricture or damage from an over-enthusiastic initial catheterisation, then exacerbated if it is in-dwelling. Often the crystals are forced into the urethral mucosa by the catheter unless great patience and care is taken.

Easy enough to squirt local up the patent urethra every 12 hours or less, count to 20 slowly, and manually express the bladder.

RE: Ureterotomy, hydropulsion?

ruths — Tue, 22 Sep 2015 07:08:32 GMT

What a brilliant discussion

I have used prazosin for some years now in cats and it seems to be helpful -))

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Mon, 21 Sep 2015 23:23:54 GMT

[quote user="Anthony Todd"]

[quote user="gerard mclauchlan"]prazosin[/quote]

I've been following blocked cats for many years and haven't heard of this drug, or it's use in animals and tamsulosin only recently.....

Any references? My guess is, as cats seem to have a urethral block [or at least, one assumes it's only the urethra!!] either of the two might be the answer to a teenage prayer.

[/quote]

J Am Vet Med Assoc. 2013 Aug 15;243(4):512-9. doi: 10.2460/javma.243.4.512.

Initial treatment factors associated with feline urethral obstruction recurrence rate: 192 cases (2004-2010).

Hetrick PF1, Davidow EB.

Author information

Abstract

OBJECTIVE:

To evaluate the association of treatment factors during initial urinary catheterization (IUC) of cats with recurrence of urethral obstruction at 24 hours and 30 days after catheter removal.

DESIGN:

Retrospective case series.

ANIMALS:

192 male cats with urethral obstruction that were treated at an emergency and specialty center from 2004 through 2010.

PROCEDURES:

Data were obtained from the cats' medical records. Duration of indwelling catheterization, catheterization with a 5F versus 3.5F urinary catheter, treatment with phenoxybenzamine versus prazosin, consistent administration of pain medication, and treatment with meloxicam or antimicrobials during IUC were reviewed for association with rate of recurrent urethral obstruction (rUO).

RESULTS:

Overall rUO rates were 10.94% (21/192 cats) at 24 hours and 23.57% (37/157 cats) at 30 days after IUC. At 24 hours and 30 days after IUC, rUO developed in 10 of 140 (7.14%) and 20 of 110 (18.18%) prazosin-treated cats, respectively, compared with 10 of 46 (21.74%) and 16 of 41 (39.02%) phenoxybenzamine-treated cats, respectively. Reobstruction developed following use of a 5F or 3.5F urinary catheter in 11 of 58 (18.97%) and 7 of 105 (6.67%) cats, respectively, through 24 hours. There was no association between rUO and duration of urinary catheterization, administration of antimicrobials or meloxicam, or consistent administration of pain medication during IUC.

CONCLUSIONS AND CLINICAL RELEVANCE:

At 24 hours and 30 days after IUC, rUO rates in prazosin-treated cats were significantly lower than rates in phenoxybenzamine-treated cats. Reobstruction rate at 24 hours was significantly lower when a 3.5F versus 5F urinary catheter was used.

RE: Ureterotomy, hydropulsion?

Anthony Todd — Mon, 21 Sep 2015 23:17:05 GMT

[quote user="gerard mclauchlan"]prazosin[/quote]

I've been following blocked cats for many years and haven't heard of this drug, or it's use in animals and tamsulosin only recently.....

Any references? My guess is, as cats seem to have a urethral block [or at least, one assumes it's only the urethra!!] either of the two might be the answer to a teenage prayer.

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 22:48:52 GMT

[quote user="Anthony Todd"]

[quote user="gerard mclauchlan"]probably because majority of ureteral obstructions are in cats and no reason tamsulosin would be more specific/efficacious than prazosin in this species as far as I am aware. [/quote]

As "difficult" blocked cats are so much more prevalent than dogs I wonder why the drug isn't promoted in cats more widely?

[/quote]I just think there is a lack of evidence that it would be any more effective in cats than prazosin. I used the tamsulosin in the US so not sure about the availability here in the UK either.

RE: Ureterotomy, hydropulsion?

Anthony Todd — Sun, 20 Sep 2015 22:44:08 GMT

As "difficult" blocked cats are so much more prevalent than dogs I wonder why the drug isn't promoted in cats more widely?

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 22:40:52 GMT

The stents themselves cause passive ureteral dilation - we pass the stent over a microwire and don't tend to use any other device to dilate the ureter in our patients. Most stones actually remain in the ureter and don't pass into bladder but the stent/sub allows passage of urine around the stone and relieve the backpressure/pain associated with hydronephrosis. It is perhaps due to the entry of the stents around the trigone area that cause some of the irritation whereas since the SUB is placed at the apex is causes less irritation is our current thinking.

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 22:34:00 GMT

[quote user="Anthony Todd"]

[quote user="gerard mclauchlan"]

What would be your cost effective way of treating an obstructed ureter ?

[/quote]

Hopefully someone will do a trial on tamsulosin, 'cos it is widely used [sorry] in humans and appears to be the drug of choice, and first line approach in ureters blocked with a stone, certainly in the UK

[/quote]

I have used tamsulosin for urethral relaxation in dogs (reflex dysnergia cases for example) sometimes instead of prazosin. Both are alpha-1 blockers so have same mechanism of action but tamsulosin is thought more specific in dogs for canine receptors (and probably people I presume from your experience) but I don't know anyone favouring it over prazosin for ureteral obstructions as yet - probably because majority of ureteral obstructions are in cats and no reason tamsulosin would be more specific/efficacious than prazosin in this species as far as I am aware.

RE: Ureterotomy, hydropulsion?

Anthony Todd — Sun, 20 Sep 2015 22:16:50 GMT

[quote user="gerard mclauchlan"]

What would be your cost effective way of treating an obstructed ureter ?

[/quote]

RE: Ureterotomy, hydropulsion?

Anthony Todd — Sun, 20 Sep 2015 22:08:14 GMT

[quote user="gerard mclauchlan"]pain when urinating and bladder irritation.[/quote]

The pain on urination wouldn't be anything to do with the placing of a ureteric stent but rather the necessary dilatation of the urethra to get the stent etc into the urethra via the bladder, I would guess?

Mine, again, I assume, was removed with the same device that grabbed the stone...

My sensory perception is that it is like those things you see grabbing large amounts of scrap metal and loading it onto a large lorry....

RE: Ureterotomy, hydropulsion?

Andrew Kent — Sun, 20 Sep 2015 20:07:15 GMT

[quote user="Sarah Keir"]But cost a small fortune...[/quote]

One of the benefits of the SUBs is that they tend to work out more cost effective than stents as they cost less, are often quicker to place. But they are a referral surgery and (ideally) require intra-operative fluoroscopy so there will always be a cost implication of that.

Andy

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 20:00:14 GMT

What would be your cost effective way of treating an obstructed ureter ?

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 19:59:20 GMT

Similar costs to stents and ureteral surgery in referral practices as a much quicker procedure generally so anaesthesia time/costs reduced. Given that ureteral surgery even when performed by specialists carries around 25% mortality rate I would spend my money on the SUB.

RE: Ureterotomy, hydropulsion?

Sarah Keir — Sun, 20 Sep 2015 19:56:28 GMT

[quote user="gerard mclauchlan"]

Very well tolerated, quick to place (with appropriate training and equipment) and significantly lower complication rates than traditional surgery and stent placement in cats.

[/quote]

But cost a small fortune...

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 18:43:35 GMT

Very well tolerated, quick to place (with appropriate training and equipment) and significantly lower complication rates than traditional surgery and stent placement in cats.

RE: Ureterotomy, hydropulsion?

Evelyn Barbour-Hill — Sun, 20 Sep 2015 18:41:26 GMT

Crikey.

Thank you.

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 18:38:16 GMT

Subcutanous ureteral bypass - designed by Norfolk medical with Chick Weisse and Allyson Berent. A nephrostomy tube to a port to a cystotomy tube.

http://www.norfolkvetproducts.com/subsystem.html

RE: Ureterotomy, hydropulsion?

Evelyn Barbour-Hill — Sun, 20 Sep 2015 18:34:13 GMT

What is SUB please?

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 18:11:15 GMT

The location of the stone is probably also important in terms of the success of medical management

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 18:08:17 GMT

Hi Anthony,

In humans stents are often poorly tolerated (if they are placed they are typically now removed after 72 hours) and are associated with pain when urinating and bladder irritation. These side effects seems to be reported commonly in cats which is why the SUB devices are now more used for ureteral obstructions in cats but stents appear well tolerated in dogs. Medical management in veterinary patients to move ureteral stones (fluids, parzosin +/- mannitol) normally isn't that successful unfortunately in my opinion. Stents allow passive dilation of the ureter and therefore passage of the ureteral stone into the bladder where it is normally urinated out.

RE: Ureterotomy, hydropulsion?

Anthony Todd — Sun, 20 Sep 2015 17:55:36 GMT

Speaking with some personal experience so here goes;

Ureteric stone 1: Removed under GA with stent in place to widen the ureter just where it goes over the femoral artery etc.

[Presence had been confirmed at 2am in the local Nambour ,QLD via CTscan where it shows as a big shiny star, as the pain can mimic a cardiac infarction.]

Stone then grabbed and removed via the urethra [I'll spare you the gory and graphic sensory sequel. stone like an old sea mine, around 4mm diam.

Ureteric stone 2, same side:

CT scan in London to confirm, on analgesia and ureteric dilator by mouth [forgotten the name but I've mentioned it before.

Referred to NHS via mutual consultant and mechanical removal dismissed, continued with dilator drug and passed 1cm stone 4mm diameter within 48hours; no post pass haematuria or pain. The impression given was that mechanical dilation and removal was so last century.

Hopefully someone will start using it in animals [will post name when I remember it] as it seems to have so many advantages. it's widely available under names like "Big Boy" etc. so it doesn't sound very toxic dose wise....

RE: Ureterotomy, hydropulsion?

Glenn Hodgson — Sun, 20 Sep 2015 16:25:59 GMT

Thanks for the advice.

I worked up this dog further this week. There was zero contrast in the ureter on the poor side. doppler showed very very minimal blood flow in the kidneyand no pelvis to be seen.. On this basis I am going to leave it where it is unless problems show themselves.

I now suspect thisis a congenital renalbissue with concurrent bladder stones. Really appreciated out new scanner with linear prob this week.

Had a good read on scents this week.

RE: Ureterotomy, hydropulsion?

gerard mclauchlan — Sun, 20 Sep 2015 13:33:11 GMT

Hi,

I agree that ureteral surgery is generally contraindicated now with the development of IR procedures. I have just spent six months training in IR at the AMC in New York and would not let azotaemia or loss of parenchyma put me off placing a ureteral stent in this case. I have seen many cats and dogs with minimal parenchyma who even only 1-2 weeks of having an obstruction removed have shown significant ultrasonographic improvement in parenchymal tissue. Hydropulsion not possible with ureteral stones - options are stent, SUB or surgery and the preferred option in most cases (in my opinion) would be stent.

RE: Ureterotomy, hydropulsion?

Andrew Kent — Sun, 20 Sep 2015 09:51:59 GMT

Hi Glenn,

I agree with Tim that, since people have had more experience with interventional management of these kind of things we see rarely suggest ureterotomy, and I don't think hydropulsion is possible with ureteral stones.

In a dog of this size a ureteral stent could be placed cystoscopically by somebody with experience of that technique - minimally invasive and quite a quick procedure, but usually requires referral. Its also much cheaper than surgery (in my hands anyway).

The difficulty is assessing residual renal function in cases like this and we don't really have a good way to do that, but if there is no visible renal pelvis then it is likely that it is pretty end stage and in that case we don't really know the benefit of an intervention. But I would not write off a kidney based on appearance alone.

Then the challenge is optimising the other side and preventing the same thing happening there.

Andy